title: Local INR calibration of the Owren type prothrombin assay greatly improves the intra- and interlaboratory variation. A three-year follow-up from the Swedish national external quality assessment scheme.
mesh_terms: D002138:Calibration; D019411:Clinical Laboratory Techniques / Q000592:standards; D006801:Humans; D019934:International Normalized Ratio; D015588:Observer Variation; D011517:Prothrombin Time / Q000592:standards*; D011786:Quality Control; D015203:Reproducibility of Results; D013548:Sweden